Polycarbonates are synthetic thermoplastic resins that may be derived from bisphenols and phosgene, or their derivatives. The desired properties of polycarbonates include clarity or transparency, high impact strength and toughness, heat resistance, weather and ozone resistance, and good ductility. They are useful for forming a wide variety of products, such as by molding, extrusion, and thermoforming processes. Such products include articles and components that include auto parts, electronic appliances and cell phone components. Because of their broad use, particularly in electronic applications or visually oriented applications, such as light covers, see-through protective coverings, lenses, and transparent films, it is desirable to provide polycarbonates with excellent weatherability, heat resistance, impact strength, and transparency.
Prior means of improving impact performance of polycarbonates have often resulted in articles of manufacture that have a significant loss of heat resistance and/or transparency. Polysiloxane polycarbonates have provided improved impact strength performance and improved solvent resistance with substantial retention of transparency compared to PC homopolymers. However, polysiloxane polycarbonates exhibit lower heat resistance compared to other polycarbonates and thus their utility is limited in some commercial applications.
There is a need for producing blends of high transparent and heat resistant polymers without substantially compromising the desired transparency and impact strength properties.